A conventional non-porous implant of a screw type and a conventional porous implant manufactured by a high temperature sintering are described with reference to FIGS. 1 and 2.
FIG. 1 is a perspective view illustrating a porous screw-type implant manufactured by a mechanical processing according to a conventional art. FIG. 2 is a front view illustrating an implant manufactured by a high temperature sintering according to a conventional art.
A screw-type implant 10 is manufactured by a mechanical processing using a milling machine 20. Thus, a processing is very difficult, and a lengthy processing time is required. Also, due to a formation of an oxide film by a secondary processing, a manufacturing cost is high. In addition, a bonding power is poor due to a small contacting area to a bone or a fibrous tissue when implanted into body tissue, and therefore the implant 10 can be easily removed from the body tissue. In the case that a large-sized implant is implanted into body tissue so as to overcome this problem, a treatment time period becomes lengthy, and the implant can locally be implanted into only body tissue having a relatively high bone density and having a large size.
In effort to overcome these problems, a method of manufacturing a porous implant by sintering metal powders at a high temperature has been introduced.
As shown in FIG. 2, metal powders 30 are put in a mold 40 and sintered at a high temperature during a long time period. Or, as shown in FIG. 2B, after putting the metal powers in the mold 40, a bar 50 is inserted to pass through a central portion of the metal powders 30, and the metal powders 30 are sintered at a high temperature during a long time period.
However, the method of FIG. 2 has a problem in that a metal inherent nature variation, a low durability, a surface variation, a lengthy sintering, and a high production cost.
Accordingly, there is a need for a technique of manufacturing a new implant in which a production cost is low, a contacting area between the implant and the bone is improved, a bonding power between the implant and the bone, a durability is high, a life span is lengthy, a treatment period is short, and a compression strength can be adjusted by adjusting a size of the implant.